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