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