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