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