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