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