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