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)(11,16)(12,23)(13,18)(14,27)(15,19)(17,25)(20,36)(21,30)(22,32)(24,34)(26,35)(28,31)(29,37)(33,39)(38,40) involution — undirected(2,6)(3,4)(7,8)(9,11)(10,16)(12,20)(13,21)(14,28)(15,22)(17,33)(18,30)(19,32)(23,36)(24,37)(25,39)(26,38)(27,31)(29,34)(35,40) involution — undirected(9,12,15,26)(10,17,19,34)(11,20,22,38)(13,25,14,24)(16,29,32,33)(18,35,27,23)(21,39,28,37)(30,36,31,40)(1,3)(4,5)(6,7)(9,13,15,14)(10,18,19,27)(11,21,22,28)(12,24,26,25)(16,30,32,31)(17,23,34,35)(20,37,38,39)(29,40,33,36)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.