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