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