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