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