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