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