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