If you don't want to keep in touch, don't. It's simple. However, your classmates may be good for networking, and could pass along job openings or whatnot, so I personally wouldn't completely cut myself off from all contact. Drama? Yep, who needs it... better off without it by far!
And yes, my class has a few cliques, people tend to gravitate towards like-minded classmates. I know I have made a few friends with some people I had initially written off for various reasons. Once we got to know eachother better, that all changed!
I definitely plan to keep in touch with some in my class, others who bring drama and chaos I can do without. But even after graduating, I can guarantee you one thing, there will be drama in the workplace as well, so you might as well learn to distance yourself, stay out of it, deal with it or ignore it. There will always be drama of some sort, unfortunately no matter where you go.