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