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