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