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