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