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