There are a couple of things you can do and I guarantee you he will think it's hotter than the sun if you did.
You can guide his hands to your clit and put pressure on his finger where you want it and softly say something like "that feels really good, don't stop". You can rub the area yourself while he's on top or in whatever position you're in at the time.
You can pillow talk about it afterwards. "That was really great, I loved it when you touched me with your hands."
Or you can simply sit down and explain that women orgasm in a variety of different ways, you happen to be able to orgasm clitorally instead of vaginally and that it's no disrespect to him but that's just the way it is.
Dr. T. Ken Taylor has discovered that the nerves responsible for female orgasm divide in a variety of ways when we're very little girls. Some women get all the sensation in their vagina and they don't enjoy clitoral stimulation and some women like a little bit of both, while still there are women who can only orgasm via clitoral stimulation.
Be open, be honest and you'll be surprised at what you receive in return!