The turbocharger increases internal combustion engine power in a rather clever way. The impeller is rotated by exhaust gas from burning fuel, and it pumps air into the engine under pressure.
As a result, more air enters the engine, meaning more fuel can be burned, so with the same engine displacement, you can get greater power.
To draw a turbocharger, you need to imagine how it works. Start with the outer shape in the form of a snail shell. Then inside, a circle with an impeller. All that remains is to add the intake, exhaust, and mountings.