To answer the question in the title – you can just be honest and say that you don’t really have a specialty yet, if your talking about a specific role you’re interested in then recount some positive experiences or skills you have that relate to that role.
Not having a specialty isn’t really a bad thing, nor is it unexpected given that you are just starting out, after all most CS education courses are quite broad by design. So this shouldn’t be a massive impediment to getting entry-level roles. Yes some prospective employers will be looking for someone who is stronger in certain areas that match their business need but others will be looking for someone they can shape into a role and there may even be those who actively prefer a “jack of all trades” candidate! This is especially true of small companies as they can’t afford to have a specialist in each area – my first tech job after graduation after graduation had me doing web development (front and back end), Windows applications, Windows services, server administration/infrastructure, and first line tech support!
Fast forward 7 years and I have specialized somewhat since then but I still have a fairly diverse skill set to the point where I usually have 3-4 versions of my CV which are tailored to different types of role in order to highlight the skills and experience that they are looking for.
At the risk of straying into career-advice here I would say that having read both this question and your earlier one it seems that you are utterly overwhelmed with the possible options you have and you’re tying yourself into knots over it. I’d point out that choosing what you do straight after graduation is not about finding your forever job so try not to overthink it. I’ve known many people who had very definite career plans for after school or university and very few of them are now doing what they thought they would be and even fewer of them went straight into their “planned” career. So cast a wide net for any jobs you think you can do (if they look interesting to you then that’s a bonus) and start applying, once you’ve got a couple of years of real world experience you’ll probably have a much better idea of the sorts of roles you want to be doing.
