I don't know that there's a style guide per se; every organization tends to have their own style guide that defines preferred colors, fonts, etc. Tableau is set up with default colors and fonts that form a de facto "Tableau style".
What you will find for Tableau are guides to best practices, both for the efficiency of the workbook and for effective communication. Start with these links:
Thanks for your reply. I came across this post, but I cannot access the link. Can you access it?
Thanks for your reply. Some organizations do have a style guide which will help users who are new to Tableau to refer it while building dashboard. I was looking for an idea how to build the document and how/what all information is included.
Try to create step by step document for creating new chart in tableau. User can easily workout.
Please refer the sample steps