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