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