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