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