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