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