Temporarily plug kitchen faucet spray hose inlet
It's hard to see the size but something like a peice of a garage hose and a gear clamp would do the trick. 

This is a gear clamp with a handle https://www.mscdirect.com

One with a handle will be helpful because it's tight up there. Cut a section of garden hose, gear clamp it on with one of these

Female hose capwww.homedepot.com

Or a variation of this concept. 
P.S. I would advise against leaving a temporary water solution like this unattended. Shut off the water if you are leaving.