questions installing an AGP card

I have an older computer, Sony Vaio PCV-RX470DS. I wanted to upgrade the video card and found a good deal on one but now I am not sure if I am installing it correctly or it if it is even compatible. The card I purchased is: SAPPHIRE 100148ADVL Radeon X1600PRO 256MB 128-bit GDDR2 AGP 4X/8X Video Card

The motherboard supports 4x, and the card claims it is 4x/8x, so I assumed it would work with my computer. I plugged it in and it has an extra cable that came with it. The cable has one small plug which fits into the card. I have no idea where the other two go, but they will plug into each other, although I doubt this is how it should be installed.

When it is installed without the extra cables, it produces multicolored vertical lines on the monitor. Where do I go from here?

Any advice is greatly appreciated. Thanks.

 

the plugs if they are 4 pin then ONE plugs into a power supply dongle (same thing that plugs into hard drives etc) to provide card with enough power to run right