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