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