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