There are a couple of different things to think about here.
First - surface tension can be thought of as "energy needed to create surface area". In that regard, you can think of a liquid water surface like a 2D spring: the more you stretch it, the more energy it costs. But it is nothing like a spring in the sense that the energy per unit area is constant (where in a spring energy goes as the square of the displacement).
You can then imagine that the force will act to make the surface smaller (that is energetically more favorable) - in whatever direction it needs to push in order to achieve that.
But there's a second important factor in most situations: there is often another (solid) surface in the picture, and there will be some forces between the liquid and the surface. If the surface likes water, we call it hydrophilic, and it is energetically favorable to create a large surface area where they touch. Unfortunately, if there is a large contact area of liquid and solid, there is an equally large area of liquid not touching solid (in the case of a plane) which is energetically not favorable. And so you get an equilibrium, where the liquid will be at a certain contact angle. At this point, you have some forces pulling on the liquid to make it bigger, and others to make it smaller.
If you have a hydrophobic surface, then the liquid will try to minimize its contact area ("beading"). Again, as it does so the area exposed to air will increase.
Once you ask yourself "what is the shape the liquid wants to be to minimize the energy" you will figure out the direction of the force.
Best Answer
What I knew and what I found relevant is "The high surface tension of mercury is due to intermetallic bonding. This bonding creates a strong "desire" for Hg atoms to interact with each other, versus their surroundings. In contrast, the surface tension of water is due to hydrogen bonding, a much weaker force that is easier to overcome." I found this answer on quora and it seems good because Hg atoms share an intermetallic bond which is much stronger that the hydrogen bonds between water molecules." This seems all right but what I found https://chemistry.stackexchange.com/questions/44898/why-is-mercurys-surface-tension-so-high-when-its-viscosity-is-low is closely related and it does raise a question on properties of mercury !