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