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