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