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