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