Making a figure for an academic project

I am making a figure which will feature in an academic paper we are writing. I have a basic version but want it to be made to look a bit more professional. It is basically a human cell with some pathways. I think it is probably quite simple for someone with graphic design experience but I can only use paint and it looks terrible! Could pay slightly more if it could be done quickly and they could ensure revisions if needed. Thanks :)