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