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