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