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