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