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