One vertex per element, one color per generator, with an edge from x to x·s.
(2,4)(6,10)(7,12)(13,14)(15,23)(16,17)(18,27)(19,21)(20,24)(22,25)(26,28) involution — undirected(5,6,9,10)(7,11,12,8)(13,15)(14,20)(16,25)(17,27)(18,26)(19,24)(21,23)(22,28)(1,2,3,4)(5,7)(6,11)(8,10)(9,12)(14,21)(15,24)(16,26)(22,27)(5,8,9,11)(6,7,10,12)(13,16,19,26)(14,17,21,28)(15,25,24,18)(20,27,23,22)(13,17)(14,16)(15,22)(18,20)(19,28)(21,26)(23,25)(24,27) involution — undirected(13,18,19,25)(14,22,21,27)(15,26,24,16)(17,20,28,23)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.