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