Let the Sylow $p$-subgroup $P$ of the group, $G$
Then can we say the Sylow $p$-subgroup always commutative?
This is definitely true when the order of $P$ is a prime number or its square. But the other case, like the order is a cubic or a higher power of the prime number, $p$.
I couldn't find any counterexample.
A popular counterexample at this site are the $2$-Sylow subgroups of $S_4$:
Sylow 2 subgroups of S4
Are all Sylow 2-subgroups in $S_4$ isomorphic to $D_4$?
The dihedral group $D_4$ of order $8$ is clearly non-abelian.