To me this sounds like a polite rejection. Depending on your culture this may differ.
If you push harder, likely either you will find a stronger rejection (though this isn't necessarily a bad thing, just confirms where you stand), or in a worst case scenario you will convince them to supervise you but you will never receive the supervision you need and find yourself like many of the question askers here who can't get advice from their advisors when they need it and find themselves lost in academia.
An active supervisor is much more useful to you than a "best professor" who never answers your emails.
I would probably respond with something like, "It sounds to me like you think you are too busy to take me on as a student, and that I should find someone else to supervise me. Is this correct, or should we plan to speak again in (several weeks/a couple months) to discuss?"