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