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