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