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