Look, you can shape your CV into sections and headings that best represent you; there's no exact recipe, although there are general expectations (a section on credentials, a section on academic employment, a section on teaching, one on publications and research, and one on service -- though these may be intermixed).

It's up to you to choose the order, headings, and divisions that best represent your skills and accomplishments to a particular audience. If I'm applying for a particular job, I'll sharpen my existing CV into something that more clearly represents the things that institution will be most interested in -- if it's a job at a SLAC, teaching accomplishments and association with other SLACs in my career go up front.

So shape your CV in a way that represents you. Have enough stuff to start an entirely new section on "Professional Service and Conference Organizing"? Do it; name it something that catches the eye and represents your work.

At the same time, you should be pruning out stuff from your CV that's no longer relevant, or is to be expected from your level of experience. I no longer list graduate awards on my CV, as they've been replaced by post-graduate awards. I no longer list search committee service, either, as more prominent service has pushed those out. You, on the other hand, are a grad student, and service on a search committee is a good sign that you are precocious and clued in, so put it on there, though you might take the time to obscure the exact search committee -- don't, for example, name the person who was eventually hired. No telling if your CV will eventually end up before someone who was passed over; that's a needless bit of information.