Here are some concepts related to Alan Turing's life/work (other than ones in the brief & the general comment section) that might help you in terms of visual concepts for the design. The previous themes relating to the main aspects of his life are most important, but if an extra visual concept is needed, these might be useful (but not at all necessary):
- Fibonacci numbers (1,1,2,3,5,8,13,21,34,55,etc etc) series that he studied and from which the golden ratio is derived.
-Sunflowers (as their seen distribution is defined by the Fibonacci numbers as Turing predicted).
-Turing Test (determining if interacting with human or machine).
-CAPTCHA ("Completely Automated Public Turing test to tell Computers and Humans Apart") developed much after his dead but inspired by his Turing Test.
-Robots behaving like or trying to pass as humans.
-Running for sport (he was a very good distance runner).
-Way too late government pardon for being gay (almost 60 years after he died).
-Turing Machine (composed mostly of long thin pieces of paper with ones or zeroes printed).
NOTE: The illustrations attached are for inspirational purposes only. The are not owned by me and are included here to illustrate a sense of style, as examples. Please do not assume that this is exactly what I want, they only offer a guide.