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