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