Widzew was founded in 1910. This is a very common sight for graffiti.
The Star of David takes the place of the 'K' in ŁKS. Apparently, in Lodz, is an insult to call someone a Jew. Most graffiti like this has the Star of David since it's common to call ŁKS and their supporters Jews. I think the chant went like this: "ŁKS, Jude! Jude! Jude!"