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