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