Is there any way of representing a dative/coordinate covalent bond?
Generally, you wouldn't describe the bonds in an ammonium ion as dative bonds. They are usually considered to be proper covalent bonds. The term &quot;dative bond&quot; is typically used for bonds in (transition) metal complexes between ligands and a metal center. But for those complexes Lewis structures have lots of weaknesses and are rarely a good representation of the actual bonding. Yet they are used for the sake of convenience. Often an arrow from the ligand to the metal center is used to indicate a dative bond.

(source: uni-erlangen.de)
But just as often you see normal &quot;covalent bonds&quot; (straight lines) like in traditional Lewis structures being used.
Often both kinds of representations are even intermixed.
For a more detailed view on the subject of bonding in coordination complexes and its representation have a look at this answer of mine.