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