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