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