There should be 2 adjusters, one at the top of the cable and one at the bottom. Your user manual should explain how to adjust this. In simple terms the top of the cable, near the lever, does fine adjustments and the adjuster at the bottom of the cable, near the clutch, does larger adjustments.
Before you mess with it take some pictures so you can see what it was originally like in case you need to put it back to how it was.
Even before this make sure you are not confusing span with adjustment. The span is how far you have to stretch your fingers to get to the clutch lever to pull it in. If this is what you need, due to smallish hands or fingers or it is just plain uncomfortable, then you really need to look at adjustable levers. Before I post a link be aware that they are NOT cheap and most bikes do not have adjustable span levers as standard. An example of adjustable levers is HERE.