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