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