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