Guys i need a little bit of help I am Stuck :s (btw sorry for my english)

I have to do a bejeweled project but first the Uml diagram of it...

I did some classes and whatever and professor said it was completely wrong...

Well, without thinking in the graphic part I did something like this:

Class game with method startgame();

Class pieces ;

Class board where I get 2 method 1 to generate random pieces and other to get the pieces how the user wants from a .txt

Class moves where I get method to check if the move is correct and eliminate the pieces that were correct...

And for start is what I could do :s

Can anyone help me with my thinking problem?

PS: one more note the game has 2 kinda ways: with time and without time and each one has 10 lvls to go...