You need to turn every switch to the left, and only in two exception to the right again later. Most of the time you get access to one new switch after using one, so the order in which you do the switches should be very obvious.
Every switch is turned to the right at the start, which means every switch turned to the left was already used at least once.
The riddle wasn't change, the solution is still the same as in the walkthrough.
I made some images to help people find the way:
