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