Interesting that Greek is so isolated, even though so many European languages are derived from it. Maybe it's because Greek was essentially a dead language that was reintroduced, so other languages had drifted far from it?
How is that? Haven't they continued to speak it in Greece all these years? Granted, modern Greek is different than the classic version of the language, but that's to be expected over thousands of years...
It's stuff like that which can't be drawn in a chart like this.
I could be wrong (this is well outside my area of expertise), but I think maybe you're thinking of Latin?
Greek words in English are rarer, and are generally not core vocabulary, e.g. "telescope", "bacteria", "paragraph", "angel".
There are Greek cognates, which found their way into both English and Greek from their common ancestor Indo-European. These are harder to recognize. Examples include ἔργον which is cognate with "work", and πέτομαι/πτερόν (I fly/wing) which are cognate with "feather".
For example, I saw a truck labelled "ethniki metafora". Pretty sure it doesn't literally mean "ethnic metaphor" though! (I think the proper translation would be "national transport".)