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