You can submit your China visa applicaiton to Chinese embassy in Saudi Arabia through two offices mentioned above on this page. As your situation, you can either apply for a tourist visa L or a business visa F. The requirements are as follows:
1. Original passport and a photocopy of its pages with personal information.
2. A fully completed Visa Application Form with your signature.
3. An original letter from your employer. It should contain your name, nationality, occupation, purpose of the visit, the planned date of entry and financial conditions.
4. A photocopy of a valid residence permit in Saudi Arabia.
5. A passport photo with white background.
6. For business visa: An invitation letter from the Chinese side (original or a photocopy/fax).