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