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