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