That is how I would take it.It looks like they have a 7.2v NiCad pack hooked up.The specs give torque ratings for 4.8 up to 8.4 v, so you could likely use 4 alkaline batteries to power the servo to test things. (or any source between 4.8 and 8.4v that can provide a decent amount of current)But do use a separate power source from the Arduino. Those are monster servos. You want them on separate sources to prevent voltage drop on the Arduino which will cause all kinds of problems.
Do the wires not have connectors ? The picture seems pretty clear unless the wires are bare.If the wires are bare, you need to get the diagram for your servo.