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