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