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