Both are used, and in practice there is little difference in meaning.
However, the collocation varies by corpus and timeframe. In English fiction, the adjective is still preferred:
Although the preference is not quite so strong in overall writing:
Meanwhile, over in Britlandia, the trend is different:
As John Lawler observes in comments:
Actually the trend is the same. You can see from the graphs that the noun compound is gaining ground while the adjective is losing. In Britain, it's just a bit more advanced, that's all. Frequently used phrases tend to shed unnecessary morphemes once they're firmly linked together. Consider soft shell crabs and soft-shelled crabs, for instance.
In any event, education is only ever a noun, never an adjective. That means it can only be modified by adjectives like compulsory — not by adverbs like very the way educational can.
Per the OED, it means:
The systematic instruction, teaching, or training in various academic and non-academic subjects given to or received by a child, typically at a school; the course of scholastic instruction a person receives in his or her lifetime.
However, this noun can also easily be used as an attribute of another noun: education policy, education system, education funding, education legislation.
The adjective educational is nothing more than the adjectival form of the word education. It means:
Of or relating to the provision of education.
It gets used to modify nouns as in educational opportunities, educational system, educational cartoons, educational psychology.
Another adjective with identical meaning but far less frequency is educative.
There’s perhaps some theoretical ambiguity with the attributive noun, but I really don’t think people will often read higher education level as a level of higher education rather than a higher level of education.