You should be able to do it from here (although, I'm using an older version so it's possible that somethings might have changed since then):
It has changed.I just checked that and I couldn't find any option to copy or save the QR code image in request tab. In the newer version, you should go to "Addresses" tab, instead.
To OP:
Go to "Addresses" tab and double click on any of addresses you want. (If you don't see "Addresses" tab, click on "View" at top of the window and then check "Addresses".)
After that, click on the "QR code" button at top right side of the window and you will see the window displayed above in OmegaStarScream's post.
Thank you hosemary, your procedure worked!
My version is 4.5.8.The other work-around I found (unattractive) was to go to one or another of the free make-your-own QR Code sites. I tested one of them with a throwaway address, and my cellphone camera read it correctly, but still... I have a lot more confidence in Electrum's own way to make a QR Code.
I like two other things about Electrum:
1) I have the program on flash drives as a Windows executable (allowing me to just bring that (traveling) assuming someone will let me use their computer)
2) Electrum allows "batch payments", so I can save a few sats when sending out BTC to several others