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