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