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