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