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