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