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