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