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