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