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