Note: A Patroller’s sense extends beyond its own visible vision cone. It sends out a sensor that travels a bit further; so don’t ever assume just because you’re out of its vision cone that you can’t be spotted by one!
Drop down into the left darkened corner of the room and as the Patroller turns around and moves right, dash right, hack the panel and then quickly (and quietly) run/jump onto the platform in front of you and immediately start crouch walking under the Patroller. If you’re quick enough (but not too quick) you’ll sneak past it.
Jump and then crouch walk past the second Patroller (leave a little bit of space between the two of you otherwise it will spot you)! Activate the terminal, flick the switch, ride the lift up and then jump up to the top floor where the switch is.
Run over to the Patroller guarding the terminal to grab its attention (remember to stay far enough away so it’s not an instant-kill), jump up to the ledge to the upper platform and hang here for a second or two before pulling yourself up and hit the switch up here once the Patroller has passed through where the doors close .
Hit the switch again to lure the Patroller back to the terminal (so stay in the shadows to remain undetected), lower the lift with the nearby switch and once you reach the bottom floor again, be careful when approaching the Patroller. If you need the [Helix] still then you need to approach this area differently to just a quick finish.
For a quick escape, as it passes across the left-side of the platform jump over and just leg it to the exit. Timed right it’ll fail to spot you as you hit the door; leaving your S-Rank intact.