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