Probably not going to be able to do that. The move of the drain pipes in the crawl space would be a lot of work, but it is very doable.
BUT, there are code issues. Depending on your local codes, there has to be a minimum of 21 to 24 " clear floor space in front of the toilet. I think the shower is too close. For that matter, there are codes about clear floor space in front of the shower, for safe entry and exit, so I think you flunk on both counts.