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