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