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