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