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