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