That is quite literally impossible, that would require Greece to not only conquer all of Anatolia (a ridiculously difficult thing in the firstplace) but also the greek military (not exactly the best in the world, or even of its immediate neighbors) to commit to a campaign of ethnic cleansing akin to the Armenian genocide on a far bigger scale targeted towards a population that is larger than the population of Greece itself. Nothing could gain Greece a victory to that extreme a degree.
I admit I'm well out of my expertise zone, but here's an idea.
Greece joins the Allies willingly and decisively during the Gallipoli campaign, turning it into a resounding success that ends with the Greeks controlling Constantinople (since they have by far the most boots on the ground). With the Ottomans reeling, Romania joins the Allies earlier and since Russia is in better shape with the Black Sea open, Romania doesn't get steamrolled but instead the Romanians, Greeks, and Anzacs knock Bulgaria out of the war.
The Ottomans are militarily weaker, and so they don't have the forces to carry out as thorough an Armenian genocide, and WW1 ends with the Allies really liking Greece because of its contributions, while Greece has a more experienced army that has also benefited from Allied know-how. Meanwhile the Turks have taken heavier than OTL casualties (including Ataturk who's dead somewhere in Gallipoli), so in the Greco-Turkish war the Greeks are able to grab a good piece of western Anatolia (maybe the old Byzantine Optimatic, Opsician, and Thracesian themes or some such-Greece grabbing all of Anatolia at this time is definitely, absolutely ASB).
The Greeks do drive out/kill the Turks in their new territories, which burns off a lot of their goodwill. But they have a lot because of WW1, and they make some back when they offer room to Armenian refugees (of which there are a lot more because of the weaker genocide attempt), a policy inspired by Byzantine romanticism caused by the fall of Istanbul. The end result, a Greco-Armenian (aka Byzantine) western Anatolia.
As for the central plateau, maybe when WW2 rolls along Greece seizes that while the great powers smash each other. Or even assuming an OTL style Cold War, Greece could take it with American approval in the name of 'forestalling the threat of Turkish communists'.
Like I said, this is well out of my expertise zone, and likely ASB. But I am interested in what others think (I may repost this in the post-1900 forum).