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