The Lewis dot structure of NaCl consists of a chloride ion surrounded by eight electron dots (four pairs) and a sodium ion bonded to that chlorine ion. Typically, ionic Lewis dot structures include the ionic charge, so the Na ion is labeled +1 and Cl is labeled -1.
The Lewis dot structure of ionic bonds such as NaCl is formed by looking at both ions and determining the fastest method of achieving a full valence shell. For chlorine, the easiest path is to gain an electron. For sodium, the easiest path is to lose an electron. Unlike in covalent bonds, the two nuclei do not share the electrons. Instead, the chlorine nuclei steals the single valence electron from sodium and the ions are bound by electrostatic effects.