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