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