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