57c is high for an idle g92 card, but i have exactly the same card and right now it's idling at 47, so I wouldn't worry about it. I've had this card for over a year and it's working fine. The temperature could be higher than mine based on your ambient temperature. Where do you live? Is it hot in the space where you keep your computer? When gaming my card would regularly hit 80c, but not higher.
Maybe turn the fan up to 75 percent if it bothers you. I have heard that you can burn out your fan that way, but it's probably not a big concern.
Also, please put your specs (everything, cpu, mobo, any overclock you may be doing) in your signature because that way people are more likely to help you and you don't waste their time.