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