First check device id and bus-id you are using during the initialization of spi (i.e. onionSpi.OnionSpi(1, 32766)
SPI is done through an adapter usually found at /dev/spidevX.Y where X is the device number and Y is the bus number, so in my case 1 is bus id and 32766 is device id
you can find your details under : /dev/ folder of your omega where file spidev would tell details for you as in above line or at below official ref.
hope you have resolved, if still any issue please revert here...