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