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