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