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