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