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)(25,26,31,32)(27,35,38,33)(28,30,34,29)(36,37,39,40)(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)(28,37)(29,39)(30,36)(31,38)(32,35)(34,40)(1,4,5,3)(2,6,7,8)(25,28)(26,30)(27,36)(29,32)(31,34)(33,40)(35,37)(38,39)(9,12,13,21)(10,15,16,20)(11,18,19,24)(14,22,17,23)(25,29,31,30)(26,34,32,28)(27,36,38,39)(33,37,35,40)(11,19)(14,17)(18,24)(22,23)(25,30,31,29)(26,34,32,28)(27,37,38,40)(33,36,35,39)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.