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