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