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