I'm guessing the far right (if i compare it to mine) is the X-axis there is a box on the Gcode page you are referring to that says "Flip build Table Axis" I would check off the box for the "X" axis. If what i suspect is happening your printer by flipping the "X" axis it should reverse what you are experiencing. I'm still new to S3D and 3D printing in general, but had similar issues when I migrated over to S3D and have years of experience in Drafting in and X, Y, Z coordinate system, so this part is easy for me (if I understand what your problem seems to be)