Where to apply for an airport transit visa?

My place of residence My visa application should be submitted to
Australia  Consulate General of Switzerland in Sydney 
Kiribati Consulate General of Switzerland in Sydney
Nauru  Consulate General of Switzerland in Sydney 
Salomon Islands  Consulate General of Switzerland in Sydney 
Vanuatu  Consulate General of Switzerland in Sydney 
Papua New Guinea  Embassy of Switzerland in Singapore 

Representation agreement

If a State does not have its proper visa section in a country or region, the delivery of a Schengen visa can be delegated to another Schengen State member with an agreement between both countries concerned.

The agreement allows the appointed representation to represent and handle Schengen visa applications within its own competence without consulting the other represented State.

Country / Region Schengen State represented by Switzerland
Australia  Hungary