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