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