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)(26,31)(27,33)(29,37)(35,40)(3,7)(6,8)(9,11)(10,16)(12,17)(13,15)(14,21)(18,24)(19,22)(20,23)(25,26,30,31)(27,28,33,36)(29,38,37,32)(34,40,39,35)(1,2)(3,6)(4,5)(7,8)(10,12)(11,13)(18,20)(19,21)(25,27,30,33)(26,28,31,36)(29,34,37,39)(32,35,38,40)(9,12,15,10)(11,17,13,16)(14,20,22,18)(19,24,21,23)(25,27)(26,28)(29,34)(30,33)(31,36)(32,35)(37,39)(38,40)(1,3)(2,6)(4,7)(5,8)(9,13,15,11)(10,17,12,16)(14,21,22,19)(18,24,20,23)(25,28)(26,27)(29,35)(30,36)(31,33)(32,34)(37,40)(38,39)(1,2)(3,6)(4,5)(7,8)(9,14)(10,18)(11,19)(12,20)(13,21)(15,22)(16,23)(17,24)(25,29,30,37)(26,32,31,38)(27,34,33,39)(28,35,36,40)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.