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