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