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