One vertex per element, one color per generator, with an edge from x to x·s.
(2,3)(5,6)(7,9)(8,15)(10,14)(11,17)(12,18)(13,19)(16,20)(21,22)(23,32)(24,35)(25,31)(26,30)(27,29)(28,34)(33,36) involution — undirected(1,2,4,3)(5,7,9,6)(8,13,16,11)(10,14,18,12)(15,17,20,19)(21,23,26,34)(22,28,30,32)(24,27,33,25)(29,35,31,36)(5,8,10,17,9,16,18,19)(6,11,12,15,7,13,14,20)(21,24,27,34,26,33,25,23)(22,28,31,35,30,32,29,36)(1,3,4,2)(6,7)(8,16)(12,14)(17,19)(21,25,26,27)(22,29,30,31)(23,33,34,24)(28,36,32,35)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.