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