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)(11,19)(12,14)(13,17)(15,18)(16,20)(21,24)(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)(9,11,13,20)(10,16,17,19)(12,22,18,24)(14,21,15,23)(25,27)(26,32)(28,33)(29,35)(30,40)(31,36)(34,37)(38,39)(1,3,5,4)(2,7,8,6)(9,12,15,17,13,18,14,10)(11,16,23,22,20,19,21,24)(25,28,30,32,31,38,29,37)(26,27,33,35,34,36,39,40)(1,4,5,3)(2,7,8,6)(10,17)(12,18)(16,19)(22,24)(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.