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