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