Canberra to Sydney Airport
Murrays runs this leg as part of its Canberra ⇆ Sydney express service, stopping at Sydney (Kingsford Smith) Airport's International Terminal (T1) roughly midway through the trip. Canberra–Sydney takes about 3–3.5 hours depending on traffic and weather; the airport stop is not the end of that trip, so times vary by service — check the live timetable for the one you're taking.
Sydney Airport drop-off
Sydney International Airport (Terminal 1), Departures level. Two official pages give a different level number for this stop — check the live page below rather than relying on a number stated here.
Sources: timetable, Sydney destination page
A booking is required for the airport stop. Murrays only stops at Sydney Airport to pick up or drop off passengers who already have a booking for that stop — you can't just flag it down.
Source: Boarding & Airport FAQs
International vs domestic terminal
This service stops at the International terminal only. To get to the Domestic terminal, use the free Terminal Shuttle, the AirportLink train, or a taxi.
Source: Boarding & Airport FAQs