One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,6)(4,5)(7,8)(10,13)(11,14)(15,16)(17,18)(19,25)(20,28,29,23)(21,24)(22,27)(26,30,32,31)(2,5)(6,8)(9,10,12,13)(11,14,15,16)(17,19,21,27)(18,22,24,25)(20,26,29,32)(23,30,28,31)(9,11)(10,14)(12,15)(13,16)(17,20)(18,23)(19,26)(21,29)(22,30)(24,28)(25,31)(27,32) involution — undirected(1,3,4,7)(2,6,5,8)(11,15)(14,16)(19,27)(20,29)(22,25)(23,28)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.