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