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