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)(26,28)(27,30)(33,36)(34,37)(2,5)(6,7)(10,15)(13,16)(17,23)(21,24)(25,26,31,28)(27,32,30,35)(29,36,38,33)(34,40,37,39)(1,2)(3,6)(4,5)(7,8)(9,11,14,19)(10,16,15,13)(12,20,22,18)(17,21,23,24)(25,27,31,30)(26,32,28,35)(29,37,38,34)(33,40,36,39)(1,3)(2,6)(4,8)(5,7)(9,11)(10,13)(12,18)(14,19)(15,16)(17,21)(20,22)(23,24)(25,28,31,26)(27,32,30,35)(29,36,38,33)(34,39,37,40)(9,12)(10,17)(11,18)(13,21)(14,22)(15,23)(16,24)(19,20)(25,29,31,38)(26,33,28,36)(27,34,30,37)(32,39,35,40)(9,13)(10,11)(12,21)(14,16)(15,19)(17,18)(20,23)(22,24)(25,30,31,27)(26,32,28,35)(29,37,38,34)(33,39,36,40)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.