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