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