One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,4,6,3,5,7,8)(9,10)(11,21,25,16)(12,18,13,27)(14,20)(15,19)(17,26,35,28)(22,38)(23,32)(24,37,29,33)(30,36)(31,39)(34,40)(2,5)(6,8)(9,11)(10,16)(12,22)(13,23)(14,29)(15,25)(17,34)(18,32)(19,21)(20,37)(24,30)(26,40)(27,38)(28,39)(31,35)(33,36) involution — undirected(9,12,15,13)(10,17,19,35)(11,22,25,23)(14,28,30,26)(16,31,21,34)(18,20,27,36)(24,40,29,39)(32,33,38,37)(2,5)(6,8)(9,13,15,12)(10,18,19,27)(11,23,25,22)(14,28,30,26)(16,32,21,38)(17,20,35,36)(24,40,29,39)(31,33,34,37)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.