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