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