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