The state [uud] is given. The transposition (12) is a symmetry of this state e.g. (12)[uud]=[uud]
Let us calculate the result under acting of the cycle (132):
(132)[uud]=[duu]
But (132)=(23)(12), so
(132)[uud]=(23)(12)[uud]=
=(23)[uud]=[udu].
Where is the mistake?