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