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