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