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