Any one who has a driveway is going to at some point get a oil stain on it. It doesn't matter how it got there, but how you are going to get it out. Because left over time, you are going to have a unsightly looking driveway.
To start you can apply some absorbent material to the oil, and this should stop it from getting worse.
A warm oil that emulsifies will also be of big help.
At any automotive store you can also find a dry compound.
But you can also try this method. In a bucket mix some warm water with dish soap. You want to then scrub the stain with a nylon brush. Take some clean rags and start to absorb the soapy solution. Then apply cat litter or even sawdust to the area. Let it sit for a few and then sweep away. You may need to re do this method several times until your stain is gone.