Currently, Zoho Books Sales Orders does not have a view to display only open orders (i.e. orders that are NOT closed).

Unlike other module views, it is not possible to set the view criteria where STATUS IS NOT = CLOSED as the only compare option is IS.  To create a view of open orders you would need to include ALL of the statuses (that's a lot of lines...).

If Zoho could include 'IS NOT' as a comparison for the STATUS field in the Sales Order custom view, it would make it significantly easier to create specific group views of sales orders at different stages (according to what the customer wants to see).