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