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