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