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