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