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