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