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