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