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