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