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