SQL command to disable all SQL Server Agent jobs in particular category.

declare @sql nvarchar(max);

set @sql = stuff(
    (
         select ';' + 'exec msdb.dbo.sp_update_job @job_name = N''' + SJ.name + ''', @Enabled = 0'
         from msdb.dbo.sysjobs as SJ
         join msdb.dbo.syscategories as SC
             on SJ.category_id = SC.category_id
         where SJ.enabled = 1
             and SC.name = 'CATEGORY_NAME_HERE'
         for xml path('')
    ), 1, 1, ''
);

-- print @sql;
exec dbo.sp_executesql @sql;