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