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