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