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