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