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