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)(11,12)(13,18)(14,24)(15,19)(16,20)(17,22)(21,23)(25,26)(27,35)(28,34)(29,33)(30,32)(31,37)(36,40)(38,39)(1,3,5,4)(2,6,8,7)(9,11)(10,16)(12,18)(13,20)(14,21)(15,17)(19,23)(22,24)(25,27)(26,31)(28,36)(29,37)(30,38)(32,40)(33,35)(34,39)(9,12,13,16)(10,17,18,21)(11,19,20,24)(14,23,15,22)(26,32)(28,30)(31,39)(33,34)(35,40)(36,38)(1,4,5,3)(2,7,8,6)(10,18)(12,16)(19,24)(22,23)(25,28,29,30)(26,32,33,34)(27,36,37,38)(31,40,35,39)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.