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