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