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