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