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