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