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