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