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