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