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