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