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)(11,13,17,22)(12,19,21,16)(18,24,23,20)(26,31)(27,34)(28,36)(37,39)(2,6)(3,7)(9,10,14,15)(11,13,17,22)(12,16,21,19)(18,20,23,24)(25,26,30,31)(27,29,34,32)(28,33,36,38)(35,37,40,39)(1,3,5,7)(2,4,6,8)(10,15)(13,22)(16,19)(20,24)(25,27,30,34)(26,32,31,29)(28,35,36,40)(33,39,38,37)(1,4)(2,7)(3,6)(5,8)(9,11,14,17)(10,13,15,22)(12,18,21,23)(16,20,19,24)(25,26)(27,32)(28,33)(29,34)(30,31)(35,39)(36,38)(37,40)(9,12,14,21)(10,16,15,19)(11,18,17,23)(13,20,22,24)(25,28,30,36)(26,33,31,38)(27,35,34,40)(29,37,32,39)(9,13)(10,17)(11,15)(12,20)(14,22)(16,23)(18,19)(21,24)(25,29,30,32)(26,34,31,27)(28,37,36,39)(33,40,38,35)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.