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