One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,4)(5,6)(7,10)(8,11)(9,12)(14,19)(15,24)(17,20)(21,26)(22,27)(23,28) involution — undirected(7,8)(10,11)(13,14,20,28,18,23,17,19)(15,21,16,26,24,27,25,22)(2,4)(5,7,9,8)(6,10,12,11)(13,15)(14,21)(16,20)(17,25)(18,24)(19,22)(23,27)(26,28)(5,8,9,7)(6,11,12,10)(13,16,18,25)(14,22,23,26)(15,20,24,17)(19,27,28,21)(6,12)(10,11)(15,24)(16,25)(21,27)(22,26) involution — undirectedA 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.