How can I display different versions of my website to the visitors randomly with the same probability?

I have three different versions of my website which I would like to show them to my visitors randomly. For example when the first user visited my webpage I would like to show version-1 of my website, when the second user visited my webpage, I would like to show version-2, for the third user displays version-3 and for the next user version-1 again and so on…

Could anyone tell me please what would be the right approach to this problem, would be any JavaScript code that I could put in my main webpage to take control of this action?