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