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