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