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