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