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