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