There is no Australian diplomatic mission in the Maldives. The Australian High Commission in Colombo manages visa and citizenship services for clients in the Maldives.
The Ministry of Foreign Affairs in Male has copies of visa application forms and may provide assistance to citizens of the Maldives in couriering applications to the Australian High Commission in Colombo.
Alternatively you can contact an international courier service in Male and have your application form and supporting documents delivered to the Australian High Commission in Colombo. You will need to pay upfront all costs in relation to delivery (and the return of any original documents).
Citizens of the Maldives who want to visit Australia as a tourist are eligible to apply online for a visitor visa at: Visitor e600 Visa Online Applications.