Liberalism isn't the same as Left. It's not even in the same political axis.
You can't really read "more liberal" as being the same as "more leftist".
Left would be something like: "I want the greatest good for the greatest number".
Liberalism would be something like: "I want people to have the most freedom to do whatever they want".
You might notice that these two things collide in things like the existence of the super-rich, were for a liberal that's a good thing (they have maximum freedom) whilst for a Leftie it's a bad thing (wealth concentration reduces the access to resources for the many hence it directly goes against the greatest good for the greatest number).
Similarly centralizing control of part or the whole of the Economy (which decreases trade freedom) to achieve greater equality is absolutelly valid within the Leftwing principles and entirely against Liberal principles.
it's only in places like the US, were the entirety of Leftwing is about 4 congressmen, that Liberalism gets confused with Leftwing.
In graphs like these it is very much all smushed together. Otherwise they'd need a 3d plot.
If you want to get really technical too, liberalism and socialism have giant grey overlap areas. Classical Liberalism wasn't just about personal freedom, but also government by the people, for the people. Which is a collective good and freedom.
It's not nearly so easy as labeling one person a leftist and another a liberal. So above I use leftist in it's colloquial meaning of getting less conservative, literally moving to the left.