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