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