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