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