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