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