Those symptoms point to a hardware failure, most likely the image sensor or related internal electronics. If the live view wavers during focusing/zooming and the captured image is covered with green horizontal lines, the problem is not a normal setting issue.

On an older compact camera like the Olympus Stylus 760, repair is usually impractical unless you have a sentimental reason to keep it. The most realistic next steps are:

• Try a reset and fresh battery just to rule out a simple glitch.
• If the problem remains, assume a sensor/electronics fault.
• Consider replacing the camera rather than repairing it.

In short: the camera likely has a failing sensor or processing circuit, and replacement is usually the sensible solution.