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