I am not able to take video with my SD card
There are two possible problems, first is that your camera does not appear to have SDXC support.  32GB is the limit of the SD and SDHC file system used on lower capacity memory cards.  To move to 64GB, you have to move to exFat which your camera may not support, so the card may simply be too big.

It is also possible the card is simply too slow to support your chosen resolution and quality level.  Have you tried stepping down the quality (to IBP or less than 1080p)?  The Ultra line of SanDisk cards is one of their slowest lines and $60 for a 64GB card is not expensive, it is dirt cheap.  To give you an idea, the SanDisk Pro Extreme SD card that I use (which is still slower than my compact flash card I use) was $150 for a 64GB card that handles 1080p video at All I frame storage.

Update: After some more reading of the manual, it appears the problem is the card size.  I see your camera doesn't even support 1080p video at all and 720p should be fine on an Ultra card.  It simply doesn't support exFat, so you will need to limit yourself to a SDHC card of no more than 32GB.  It might be worth doing some more digging on that too as there are SDHC cards listed for your camera, but none in the 32GB range (but that may simply be that there weren't any available when it was made.)  I would verify 32GB compatibility before buying a 32gb card since 16GB is the biggest listed in the manual.