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