Mission Beach Taxi operates a 24 hr Limousine service. Cairns airport to/from Sealords is $330 one way. Contact them on 0448 125 984 to book the service.
We strongly recommend you rent a car for your visit to Sealords, either at the airport if arriving by air, or at Mission Beach if arriving by bus. You can walk to the village from Sealords where there are resteraunts and cafes, but it takes 40 minutes, and you will probably want to visit attractions nearby or beyond where there is no public or private transport.
The major Car Rental companies are located at Cairns and Townsville airports. In addition at Cairns (next to the airport) and Mission Beach (Wongaling Beach very close to the Greyhound bus terminal) there is Sugarland Car Hire (www.sugarlandcarrental.com.au). At Cairns, Sugarland will pick you up/drop you off at the airport when collecting/returning the car.
The drive from Cairns to Mission Beach is easy, uncongested, and scenic passing the two highest mountains in Queensland that are covered in rainforest, and huge sugar cane farming acerages in the valleys. You may want to visit some of the attractions along the way such as Josephine Falls or Mamu Skywalk and/or Paranella Park that are a little more than half way along the route (see attractions), or save these as a nice day trip from Sealords. The drive from Townsville to Cairns is similarly easy, uncongested, and scenic; as you pass over the Cardwell Gap there are spectacular views of Hinchinbrook Island with its large old volcanic mountainous ranges along its lenght - also see attractions for activities along the route.