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