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)(26,28)(29,37)(31,34)(35,39) involution — undirected(2,5)(6,8)(9,10,13,14)(11,15,17,20)(12,16,19,21)(18,22,23,24)(26,28)(27,33)(32,36)(35,39)(1,2)(3,6)(4,5)(7,8)(9,10)(11,15)(12,16)(13,14)(17,20)(18,22)(19,21)(23,24)(25,26,30,28)(27,31,33,34)(29,32,37,36)(35,38,39,40)(9,10)(11,15)(12,16)(13,14)(17,20)(18,22)(19,21)(23,24)(25,27)(26,31)(28,34)(29,35)(30,33)(32,38)(36,40)(37,39) involution — undirected(1,2)(3,6)(4,5)(7,8)(9,11,13,17)(10,15,14,20)(12,18,19,23)(16,22,21,24)(25,28,30,26)(27,34,33,31)(29,36,37,32)(35,40,39,38)(1,3,4,7)(2,6,5,8)(9,12,13,19)(10,16,14,21)(11,18,17,23)(15,22,20,24)(25,29)(26,32)(27,35)(28,36)(30,37)(31,38)(33,39)(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.