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