I think that’s fine. I think it’s fine to say that your school, like any other, has cliques and that there is little overlap between most of them and that you have found a way to move between them based on your interests.
You might want to think about how the cliques formed and whether that should define people. In our town, kids who played certain sports tended to band together mostly because of their shared schedule – they were in the same place after school and on weekends, and they sometimes traveled together. How did that become more important than what they were interested in? Was it because they didn’t really talk to know of each other’s interests?
Not saying you should take it in this direction, but it’s a worthy thought as you frame your essay because it may explain why you are moving between cliques and others are not.