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