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