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