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