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