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