Symmetric Group is not Abelian/Proof 1

Proof
Let $\alpha \in S_n$ such that $\alpha$ is not the identity mapping.

From Center of Symmetric Group is Trivial, $\alpha$ is not in the center $Z \paren {S_n}$ of $S_n$.

Thus $S_n \ne Z \paren {S_n}$.

The result follows by Group equals Center iff Abelian.