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)(11,14)(15,16)(17,18)(19,25)(20,23)(21,24)(22,27)(26,31)(28,30)(29,32) involution — undirected(1,3,4,8)(2,5,6,7)(9,10,14,16,12,15,11,13)(17,19)(18,22)(20,27)(21,26)(23,25)(24,30)(28,29)(31,32)(2,6)(5,7)(10,15)(13,16)(19,26)(21,29)(22,30)(24,32)(25,31)(27,28) involution — undirected(2,6)(5,7)(9,10,14,16,12,15,11,13)(18,23)(22,25)(24,32)(30,31)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.