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