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)(13,14,16,18)(15,17,19,20)(21,22,26,28,25,30,24,29)(23,31,34,27,33,36,32,35)(6,9)(7,11)(13,15)(14,17)(16,19)(18,20) involution — undirected(2,4)(15,19)(17,20)(21,23,25,33)(22,27,30,35)(24,34,26,32)(28,31,29,36)(5,7,8,11)(6,10,9,12)(22,28)(24,26)(27,31)(29,30)(32,34)(35,36)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.