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