The version of Dansa that they are playing and dancing in the video is a three part progression known as Diaura. I'm guessing there's no official spelling. It could be Djawra or Jagura or whatever you want. When you say it, the emphasis is on the last "a".
Often, only the second and third parts are played.
Even more often, especially in the cities, they skip the first and second parts and start right away with the faster third part.
My understanding is that calling this "Dansa" is accurate. To call it "Diaura" is more specific, as there are other versions of Dansa.
Sandiya is not played or danced in this video, but one of the common dundun accompaniments for Diaura is three open strokes with a rest, similar to Sandiya.
To see a good version of Diaura on youtube, look at the videos Michel posted. His youtube name is bilibiliba. The videos say "Troupe de Kayes- Dansa". On those videos, they play all three parts to Diaura clearly.
The three men who are dancing dressed as women are professional performers. I have met them, and other men who do this, too. These three are well known, and often invited (not usually together) to do their performances at ceremonies and festivals around Kayes and Bamako.
As Bambaraken commented on youtube, Wande normally wears womens clothes on a daily basis. He also wears make-up and does his hair like a woman. He is the only male khassonka dancer that I know who does that. The other men I know only dress up to dance.
In the Video Wande is wearing a white Tshirt. Sora Sissoko is dressed in a green dress at first, and then strips off a layer to reveal a white dress. Nare is wearing yellow.
I do believe there is some cultural significance to this performing in drag, but I haven't asked a lot of questions about it, so don't know about the ancient history of dancing in drag in Khassonka culture. I have been told that some Malinke and Maraka men also do it.
More recently, however, there was a noteworthy Khassonka performer who helped popularize it. His name is Toutou Kante. He would travel around singing and dancing in womens clothes.
Toutou died very recently. 2008, I think. Nare Keita was one of Toutou's main students. Sora is a student of Nare, and Toutou. Wande is a student of one of Sora's students (a girl named Aisata Dansira) as well as learning from Sora and Nare etc..
Here's the only video I know of with Toutou Kante. Nare is also in this video. He is on the left. He dances first and then he sings when Toutou steps out to dance.
In my opinion, although there are definitely comedic aspects, this is not merely comedy. Yes, everyone laughs and has a good time, but these men are respected as great dancers, capable of performing womens' dance steps with grace and finesse, as well as performing more acrobatic steps that require great strength and endurance. Toutou and his students are also renowned for their singing ability. Toutou was just as much a singer as he was a dancer. The same can be said for some of his students. Nare has actually recently released an album. It can be purchased in Mali. At some ceremonies I've been to, Nare, or another of Toutou's students, Boubou, have actually done more singing than dancing.