Not quite... There's two positions for the sword icon. One is above the enemy's name, and the other is on the same line as the enemy's name. When it's on the same line, then you've got auto-attack on. And I think the enemy name's color changes a bit when you have auto-attacking going. I'm not certain, though, I'm terrible with colors. Auto-attacking could still probably be made easier. Like just right clicking to initiate it.