We also cannot print event sheets in Construct 2. Just like you this is a feature I would gladly see becoming available in Construct 3.
What I do, is using FastStone ScreenCapture and make a screen capture which I print to a physical printer or Nitro PDF creator.
FastStone has an option to print your screen even when parts fall off the visible area. It also let you record your actions on screen, which can be very handy.