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