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