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