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