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