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