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