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