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