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