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