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