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