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