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