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