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