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