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