It's not possible to view the files from a browser with a Service Account. This account is primarily for administrate the accounts of the users in the same domain.
Service accounts are accounts associated with a service or a project. They do not belong to a user and can only be accessed programmatically by the associated application.
Read more here: https://developers.google.com/drive/web/service-accounts#use_service_accounts_as_application-owned_accounts