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