One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,6)(4,5)(7,8)(9,10)(11,13)(12,14)(15,16)(17,18)(19,26)(20,28)(21,25)(22,23)(24,27)(29,32)(30,31) involution — undirected(2,5)(3,7)(9,11)(10,13)(12,15)(14,16)(17,19,21,22)(18,23,25,26)(20,29,30,27)(24,31,32,28)(11,15)(13,16)(17,20)(18,24)(19,27)(21,30)(22,29)(23,28)(25,32)(26,31) involution — undirected(1,3,4,7)(2,6,5,8)(10,14)(11,15)(18,25)(23,26)(24,32)(28,31)(2,5)(6,8)(11,15)(13,16)(17,19,21,22)(18,23,25,26)(20,27,30,29)(24,28,32,31)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.