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