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