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