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