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