Depends how much light pollution you have around you.
I've had friends tell me they've seen it naked eye under dark desert skies and I've certainly picked it up with binoculars. But in a city it tends to get washed out fairly easily.
My advice is to use the
lowest mag eyepiece you have so the light from the galaxy is concentrated in a smaller area in the field of view - which is why binos can find it easily. If you manage to find it with the low mag then try a high mag eyepiece. But there is no substitute for a dark sky!
My most memorable view of NGC 5128 is through a 20" at the South Pacific Star Party. Mindblowing, that was. You could see the dark dust lanes extending out either side. But you wont get that in an 8"!