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