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)(11,19)(12,22)(13,16)(14,20)(15,17)(18,23)(21,24)(25,26,31,28)(27,30,33,34)(29,32,38,36)(35,37,39,40)(1,3,6,5)(2,7,4,8)(9,11,15,13)(10,16,17,19)(12,20,23,21)(14,22,24,18)(25,27)(26,30)(28,34)(29,35)(31,33)(32,37)(36,40)(38,39)(1,3,6,5)(2,8,4,7)(10,17)(14,24)(16,19)(18,22)(27,33)(30,34)(35,39)(37,40)(1,4,6,2)(3,7,5,8)(9,12,15,23)(10,18,17,22)(11,21,13,20)(14,16,24,19)(25,28,31,26)(27,34,33,30)(29,32,38,36)(35,37,39,40)(1,5,6,3)(2,7,4,8)(9,13,15,11)(10,19,17,16)(12,21,23,20)(14,18,24,22)(25,29)(26,32)(27,35)(28,36)(30,37)(31,38)(33,39)(34,40)(9,14,15,24)(10,20,17,21)(11,22,13,18)(12,16,23,19)(25,30,31,34)(26,33,28,27)(29,37,38,40)(32,39,36,35)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.