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