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