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