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