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