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