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