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