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