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)(11,12)(13,14)(15,16)(17,18,21,19)(20,23,24,22)(25,26,30,29)(27,33,35,31)(28,32,36,37)(34,39,40,38)(1,3)(2,6)(4,7)(5,8)(9,11)(10,15)(12,13)(14,16)(17,18,21,19)(20,22,24,23)(28,36)(32,37)(34,40)(38,39)(9,12)(10,11)(13,16)(14,15)(17,19,21,18)(20,23,24,22)(25,27,30,35)(26,31,29,33)(28,34,36,40)(32,38,37,39)(1,4,5,2)(3,7,8,6)(9,13,14,10)(11,12,16,15)(17,20)(18,22)(19,23)(21,24)(25,28)(26,32)(27,34)(29,37)(30,36)(31,38)(33,39)(35,40)(1,3)(2,7)(4,6)(5,8)(9,12)(10,16)(11,13)(14,15)(25,29,30,26)(27,33,35,31)(28,37,36,32)(34,39,40,38)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.