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