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