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