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