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