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