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