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