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