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