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