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