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