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