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