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)(11,13)(12,20)(14,15)(16,18)(17,22)(19,23)(21,24)(25,26,30,29)(27,33,35,31)(28,36,38,32)(34,39,37,40)(1,3)(2,4)(5,6)(7,8)(10,15)(11,18)(17,20)(19,24)(25,27,30,35)(26,31,29,33)(28,37,38,34)(32,40,36,39)(1,4)(2,5)(3,7)(6,8)(9,11)(10,16)(12,19)(13,15)(14,18)(17,23)(20,21)(22,24)(25,27,30,35)(26,31,29,33)(28,34,38,37)(32,39,36,40)(1,3,6,5)(2,4,7,8)(9,11)(10,16)(12,19)(13,15)(14,18)(17,23)(20,21)(22,24)(25,28)(26,32)(27,34)(29,36)(30,38)(31,39)(33,40)(35,37)(1,5,6,3)(2,4,7,8)(9,12,14,22)(10,17,15,20)(11,19,18,24)(13,21,16,23)(25,27)(26,31)(28,34)(29,33)(30,35)(32,39)(36,40)(37,38)(1,4)(2,3)(5,7)(6,8)(9,13,14,16)(10,11,15,18)(12,21,22,23)(17,19,20,24)(25,29,30,26)(27,33,35,31)(28,32,38,36)(34,39,37,40)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.