One of the earliest is on The National Library of Australia website. It consists of two maps - one of Norfolk Island and the other of the south of the island. The map was created by W Bradley in 1788.
Plan of the town of Sydney on the south side of Norfolk Island, December 1793. The map was drawn by Charkes Grimes, Deputy Surveyor.
map was drawn by William Neate Chapman.
Convict Settlement - Norfolk Island includes a number of small maps of early settlement on the island. Unfortunately there is no date but they do provide an idea of the layout of the early settlement on the island.