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