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