Currently there are 3 native Telephoto Zoom lenses for Panasonic S5 and all of these lenses are autofocus (AF) type.
S5 also has a sensor based image stabilization system which means that all of these lenses will be stabilized when used on S5.
Since Panasonic S5 has environmental sealings (Weather Sealing), you may like to couple your camera with one of these 3 Telephoto Zoom lenses with Weather Sealings.