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