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