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