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