One vertex per element, one color per generator, with an edge from x to x·s.
(1,2) involution — undirected(3,4)(5,6)(7,8,12,16)(9,17,19,30)(10,14,22,28)(11,24,18,15)(13,25,26,21)(20,31,33,38)(23,35,32,29)(27,36,37,34)(7,9,18,25,12,19,11,21)(8,13,24,30,16,26,15,17)(10,20,32,36,22,33,23,34)(14,27,35,38,28,37,29,31)(4,6)(9,19)(13,26)(17,30)(20,33)(21,25)(27,37)(31,38)(34,36) involution — undirected(7,10)(8,14)(9,20)(11,23)(12,22)(13,27)(15,29)(16,28)(17,31)(18,32)(19,33)(21,34)(24,35)(25,36)(26,37)(30,38) involution — undirected(10,22)(14,28)(20,33)(23,32)(27,37)(29,35)(31,38)(34,36) involution — undirectedA 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.