The Automorphism Group of the Petersen Graph is Isomorphic to $S_5$.

Abstract

The automorphism group of the Petersen Graph is shown to be isomorphic to the symmetric group on 5 elements. The image represents the Petersen Graph with the ten 3-element subsets of $\{1, 2, 3, 4, 5\}$ as vertices. Two vertices are adjacent when they have precisely one element in common.