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