One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,6)(4,5)(7,8)(9,10,14,16,13,18,12,17)(11,15,21,22,19,23,20,24)(25,26,29,34,31,28,30,33)(27,32,39,40,37,38,36,35)(2,5)(6,8)(9,11)(10,15)(12,20)(13,19)(14,21)(16,22)(17,24)(18,23)(25,27)(26,32)(28,38)(29,39)(30,36)(31,37)(33,35)(34,40) involution — undirected(1,3)(2,6)(4,7)(5,8)(10,16)(12,14)(15,22)(17,18)(20,21)(23,24)(25,28,31,26)(27,35,37,40)(29,34,30,33)(32,39,38,36)(3,7)(6,8)(11,19)(15,23)(20,21)(22,24)(25,29,31,30)(26,33,28,34)(27,36,37,39)(32,40,38,35)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.