in the pictures you have shared its a big too much leakage but i 100% agree
this is very common issue in cg 125 engine small oil seepage which is very
annoying specially i personally don't like these oils stains alongside this issue
there is very common issue of oil leakage from tachometer cable which is
installed in clutch cover I CALL CG125 ENGINE DIRTY ENGINE it does not remain clean
Tappet cover leakage may be because of negligence of mechanics as they might not be
properly installing tappet cover may be some kinda sealant is recommended to use before
installing cover though honda mechanics says no need of any sealant
Its a pretty common issue in OHV (Over Head Valve) engines, I guess...
As a safety precaution, take out the spark plug and inspect its tip that goes in the cylinder head... If the tip is all oily, gunky, black and smells like motor oil then there's probably a head gasket leakage... In this case, your only option is to replace the seals which is a little on the 'costly' side.
Since its a Honda Motorcycle, take it to a well reputed Honda Service Center (pretty common in big cities) and get it fixed there. They may charge more than a private mechanic, but atleast you will be sure that the work done on your bike is honestly performed by trained professionals... Good luck.