WD3200bevt won't show in finder, but shows in Disk Utility

WD3200bevt won't show in finder, but shows in Disk Utility

I have a western digital my passport 320GB 2.5" SATA drive. After being put up for a couple of months, it isn't mounting to my macbook. I bought a new USB cable to test if that was the issue and it still isn't working.