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