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