Nowhere is safe, if you don't take precautions and act indifferently to what is going on around you. There are crimes against women and tourists in Goa, but plenty of women travel there in groups and even alone. So play it safe, don't blindly trust anyone, do some research on the transportation options and hotels and stay near the beach you wish to explore.
It is quite safe compared to other places:
1. Do Not argue with locals,
2. Avoid Going out alone in during late hours.
3. Do not trust anyone blindly.
4. Take care of your drinks , if you are visiting pubs. Never leave them unattended.
5. Avoid lonely beaches.
As Yogesh mentioned, Anywhere on this planet, you are responsible for your safety. t