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