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