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