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