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