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