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