A few random thoughts ;-
Start by checking you have a live feed to the coils (using a volt meter or test lamp) with the ignition on.
If not - check the kill switch is in good working order & not shorting out (i.e. strip it down & check it out).
Also check to see if the side-stand cut out switch is not sticking/shorting. (Try starting with side stand up)
Does the Sachs have a micro switch on the clutch lever that needs the clutch to be disengaged prior to starting ? .... but that is usually on the starter circuit rather than the ignition ('sparks')
But before that ..... Do the lights for the ignition circuit come on ? - If not it could be a dodgy ignition switch. .... or even a blown fuse on the ignition circuit. If fuse is gone, it could be a short somewhere in the ignition circuit - look for chaffed wires
How have you determined 'No Sparks' ? ... if with a loose plug held on the side of the engine, was it properly earthed (some people are worried about getting a shock ! ) ... It helps to get the wife/girlfriend to assist here
Are HT leads & plug caps in good order ?
Also wondering is this a 'new' problem, or is the bike a recent purchase - any other symptoms/issues with the bike ?