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