A cat purring while not meowing is a sign of happiness and relaxation. Generally, cats will purr when they are with trusted people or in a comfortable environment. This is normal and there is no need to worry; but if the cat appears to be in a bad mood, , cold nose, etc., it may also be an illness.
Tips:
You can touch the cat's chin, cheeks, head, back and other parts more often, so that the cat will feel It is very comfortable and makes a purring sound.