When you want to print the Book of Styles - you have to select this option in the print pop-up. Once selected you can decide if you need to print all types of data fields.
When you are satisfied with your selection - click on OK and the Book of Styles will appear as a PDF preview. Each page can hold up to 9 styles, they will be printed accordingly to the grouping and sorting you have used on the Thumbnail page.
Save the PDF to you desktop or print it. Here in the example of 2 styles pr page.
Read HERE how you set up the print in Admin.