I have a software called Daisy Disk and it says I only have 70 GB left in my drive. However in Finder I see 131 GB available.
How is this 60 GB difference possible?
Finder does not take into account Time Machine's Local Snapshots. The storage space of these local snapshots will be given to files if necessary and therefore the space is not actually being consumed. Daisy Disk sees these files though and takes them into account when calculating the free space.
You can disable local snapshots by turning off Time Machine completely, or to retain Time Machine functionality without local snapshots you can run the following command:
sudo tmutil disablelocal