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