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)(11,17)(12,15)(13,16)(14,19)(18,23)(20,22)(21,24)(25,26,29,31)(27,35,37,40)(28,34,30,33)(32,38,39,36)(1,3)(2,5)(4,8)(6,7)(9,11)(10,14)(12,18)(13,19)(15,21)(16,17)(20,24)(22,23)(26,31)(32,39)(33,34)(35,40) involution — undirected(3,8)(5,7)(9,12,13,20)(10,15,16,22)(11,18,19,24)(14,21,17,23)(25,27,29,37)(26,32,31,39)(28,36,30,38)(33,35,34,40)(2,6)(5,7)(10,16)(11,19)(15,22)(18,24)(25,28,29,30)(26,33,31,34)(27,36,37,38)(32,35,39,40)(10,16)(14,17)(15,22)(21,23)(26,31)(32,39)(33,34)(35,40) 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.