I think, its completely fine to put out a small C-bet on the flop. You could also go a bit larger. Some players might think, a small bet is always for value, and part of the theory behind this "downbetting" is, that people fold to much to a small sizing. And when you have the nuts, you obviously dont want people to fold to much.
I think, people sometimes get to hung up on the fact, you block top pair with top set. While this is true, its not a massively different situation from having top pair like for instance AK. Even when you bet AK on this board - which nearly everyone will - most of the range, that continue, is not AX. Its second pair, third pair, pockets pair, draws.
It would not be a big mistake to check the flop back also, and you can mix this into your game from time to time. I would lean more towards checking back though, if it was a rainbow board. You dont really want to slowplay here, and then the board runs out diamond-diamond pretty much turning your set into dust.
At the end of the day to win a big pot we need not only a big hand but also for our opponent to have another big but second best hand. If the opponent has absolutely nothing and will not pay, then slowplaying often dont change that. Instead he just fold, when you bet later, or at most you get one small bet out of him.
