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