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