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