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